The effect of bariatric surgery, on Dyslipidemias: Sleeve gastrectomy vs. gastric bypass

Mauricio Sarmiento Cobos, MD, David Gutierrez Blanco, David Romero Funes, MD, Emanuele Lo Menzo, MD, PhD, FACS, Rama Ganga, MD, Samuel Szomstein, MD, FACS, Raul J Rosenthal, MD, FACS. Cleveland Clinic Florida

INTRODUCTION: Obesity and dyslipidemias are well-known factors that affect the overall cardiovascular risk. Bariatric surgery has shown to have a positive impact on the overall lipid profiles. However, most of the studies are based on Roux-en-Y gastric bypass(LRYGB), and only a few analyze the outcomes after Laparoscopic Sleeve Gastrectomy(LSG). Our goal is to determine the overall impact of bariatric surgery, especially LSG, in the lipid profile.

METHODS: We retrospectively reviewed all the patients who underwent bariatric surgery at our institution from 2010-2015. Common demographics and comorbidities were collected as well as lipid profile, hemoglobin A1c and systolic blood pressure(SBP), preoperative and at 12 months follow-up. All tests were two-tailed and performed at a significant level of 0.05. Statistical software R, version 3.3.1 (2016-06-21) was used for all analyses.

RESULTS: Of the 1330 patients reviewed, 27% (n=360) met the inclusion criteria. The average age was 52.12±11.86 years, females composed 70.3% (n=253) and Caucasian 76.7% (n=276) of our population. The incidence of Diabetes Mellitus and hypertension was 43.1% (n=155) and 57.5% (n=207), respectively. The most common surgery were respectively LSG 63.1% (n=227) followed by LRYGB 20.6% (n=74), Revisional procedures 11.9 (n=43) and Laparoscopic adjustable gastric banding <5% (n=16).

The incidence of dyslipidemias calculated preoperatively was of 31.4% (n=113) with high levels of total cholesterol(>200mg/dL), 38.1% (n=137) with LDL>100mg/dL, 17.8%(n=64) with HDL<40mg/dL, and 66.4%(n=239) with Triglycerides>150 mg/dL.

At 12 months follow-up all lipid levels had a statistically significant change (P<0.001). Total cholesterol was decreased 4.6% (8.76 mg/dL), LDL decreased 7.2% (7.79 mg/dL), HDL increased 13.4% (6.93 mg/dL) and triglycerides decreased 32.49% (49.46 mg/dL). The incidence of patients with dyslipidemias was also significantly decreased except for high LDL levels (p=0.23), a summary is presented in table 1.

When lipids outcomes were compared between the type of surgery, no statistical significance was found between LSG and LRYGB patients. Table 2 reflects the summary between the type of surgery, gender, age, race and lipid levels at 12 months follow-up.

CONCLUSION: Patients undergoing bariatric surgery present with a high incidence of dyslipidemias. Bariatric surgery has a positive impact on the lipid profiles at 12 months follow-up. Laparoscopic sleeve gastrectomy has a similar effect on lipid levels when compared to Roux-en-Y gastric bypass. Further studies should be done to better understand these findings.